package class01;

import java.util.Arrays;

/**
 * @author Gong Cheng
 * @date 2021/2/25 9:56 上午
 **/
public class Code01_SelectionSort {

    public static void selectionSort(int[] arr) {
        if (arr == null || arr.length < 2) {
            return;
        }

        for (int i = 0; i < arr.length - 1; i++) {
            int minIndex = i;
            for (int j = i + 1; j < arr.length; j++) {
                minIndex = arr[j] < arr[minIndex] ? j : minIndex;
            }
            swap(arr, i, minIndex);
        }
    }

    public static void swap(int[] arr, int i, int j) {
        int tmp = arr[i];
        arr[i] = arr[j];
        arr[j] = tmp;
    }

    public static void comparator(int[] arr) {
        Arrays.sort(arr);
    }

    public static int[] generateRandomArray(int maxSize,int maxValue){
        int[] arr = new int[(int)((maxSize + 1)*Math.random())];
        for (int i = 0; i <arr.length; i++){
            arr[i] = (int) ((maxValue + 1) * Math.random() - (int)(maxValue * Math.random()));
        }
        return  arr;
    }

    public static int[] copyArray(int[] arr){
        if(arr == null) {
            return null;
        }
        int[] res = new int[arr.length];
        for(int i = 0; i < arr.length;i++){
            res[i] = arr[i];
        }
        return res;
    }

    public static boolean isEqual(int[] arr1, int[] arr2){
        if((arr1 == null && arr2 !=null) || (arr1!=null&& arr2 == null)){
            return false;
        }
        if (arr1 ==null && arr2 == null){
            return true;
        }
        if( arr1.length != arr2.length){
            return false;
        }
        for(int i = 0; i < arr1.length; i++){
            if (arr1[i] != arr2[i]){
                return false;
            }
        }
        return true;
    }

    public static void printArray(int[] arr){
        if(arr == null){
            return;
        }
        for (int i = 0; i < arr.length; i++){
            System.out.println(arr[i]+" ");
        }
        System.out.println();
    }

    public static void main(String[] args) {
        int testTime = 5_000_000;
        int maxSize = 100;
        int maxValue = 100;
        boolean succeed = true;
        for (int i = 0; i < testTime; i ++){
            int[] arr1 = generateRandomArray(maxSize,maxValue);
            int[] arr2 = copyArray(arr1);
            selectionSort(arr1);
            comparator(arr2);
            if(!isEqual(arr1,arr2)){
                succeed = false;
                printArray(arr1);
                printArray(arr2);
                break;
            }
        }
        System.out.println(succeed ? "Nice!" : "Fucking fucked!");

        int[] arr = generateRandomArray(maxSize,maxValue);
        printArray(arr);
        selectionSort(arr);
        printArray(arr);
    }
}
